This invention has relation to the support and lubrication of main bearings designed to permit a road roller or drum to rotate at a relatively low speed with respect to the frame of a road, earth or other surface compacting machine and to the positioning of shaft bearings in concentric alignment with the main drum bearings to support a vibratory shaft within the drum to rotate at a relatively high speed, all without the need to provide a rotating seal between parts rotating at such relatively high speed with respect to each other.
Such structures normally utilize oil sumps or reservoirs from which the lubricating oil can be supplied to the bearings. In a typical structure, for example, the drum drive assembly for a Model CA-50 road roller manufactured by Vibro-Plus Products of Stanhope, N.J., each of the slow speed main drum bearings is fixedly supported with respect to one of the side frame plates of the machine. Drum end plates at each end of the drum each support a bell-shape closed oil sump. In each of these oil sumps, an eccentric shaft is rotatably mounted on a pair of high speed bearings, one set in the drum end plate and the other set in the wall of the bell-shape sump. A cylindrical drive shaft connects the two eccentric shafts, to thus form a compound drive shaft assembly. Driving one of the eccentric shafts from outside of the drum end plate at one end of the drum will cause the other eccentric shaft to be driven as well. This structure necessitates a high speed seal between the outer races each of the high speed vibratory shaft bearings situated in the wall of the oil sump and the compound vibratory drive shaft. Such high speed seals introduce a good deal of friction and heat and, therefore, wasted energy, into the driving of the vibratory shaft. These seals tend to wear out and break down rapidly, and, being situated in a space between opposite spaced apart drum end plates, are very, very expensive to repair and/or replace.
The structure of the present invention was developed to eliminate need for any high speed seal at all in such a structure, and to provide for positive lubrication of the relatively slow speed bearing forming the connection between the side frame plates of the machine and the road roller or drum at the end of the drum through which the vibratory shaft is driven.
A companion application, simultaneously filed, patent application Ser. No. 152,683, covers an invention whereby the vibratory shaft bearings themselves are positively lubricated utilizing gravity oil flow during the relatively slow rotation of the housing for those bearings with the road roller or drum.
A search of the prior art was made on the subject of positive lubrication of bearings for concentric rotating members and the following patents were located:
U.S. Pat. No. 1,766,001 granted to Planche in June of 1930; PA1 U.S. Pat. No. 1,787,428 granted to Fekete et al in January of 1931; PA1 U.S. Pat. No. 3,301,349 granted to Williams in January of 1967; and PA1 U.S. Pat. No. 3,741,343 granted to Lindenfeld in June of 1973.
None is believed to be particularly pertinent to the present invention.
The inventor and those in privity with him know of no closer prior art than that set out above and know of no prior art which anticipates the claims made herein.